The field of this invention is directed to a hitch for heavy-duty hauling, and is more particularly concerned with a heavy-duty hitch which provides ease of coupling between a towing and a trailing vehicle without the need of accurate positioning alignment of the vehicles to effect a coupling hitch connection. Trailer hitches commonly used require accurate positioning of the towing vehicle relative to the vehicle being towed, especially when hooking up to a large trailer or implement which cannot be readily maneuvered by hand. A hitch-equipped truck is especially difficult to back up close enough to a trailer to make a hookup without an observer to direct the truck operator. Without an observer to direct the truck driver he is obliged to back the truck to where he believes a coupling connection might be made; since the hitch is out of his field of vision, he must then get out of the truck and check the hitch location. These steps are repeated as often as it takes, until alignment of the hitch and the trailer tow bar are achieved and a coupling pin installed to complete the hookup. If the trailer is relatively lightweight it may be possible to maneuver the trailer to a coupleable location relative to the hitch by hand.
One device which attempted to overcome this problem provided a pivotable drawbar member mounted to a tractor used in combination with a hydraulic cylinder. The hydraulic cylinder is connected to an extendible yoke by means of a flexible cable. Herein, the hydraulic cylinder pays out the yoke which is then connected to a tongue of a trailer. The cylinder is then charged to retrieve the yoke dragging the trailer along and locks it to the tractor drawbar. The drawbar includes a tube section pivotably supported on the frame of the tractor with a socket portion at one end thereof to receive the extendible yoke when retracted.
Hydraulic pressure maintained in the cylinder secures the yoke in a stowed position. Herein, the length of stroke of the hydraulic cylinder limits the distance the yoke can be extended to reach a trailer for hookup and the security of the connection depends on maintaining a suitable hydraulic pressure in the cylinder. Further, the non-rigid support of the drawbar from the tractor precludes the use of a coupler ball connection between the tractor and trailer. Thus, it will be seen that this device is designed only for off-road towing and is not adaptable for general use on highway vehicles or the like.